The present invention relates to a method of and to an apparatus for making so-called soft-core cigarettes and analogous rod-shaped articles of the tobacco processing industry wherein the central portion of the fibrous filler is softer than the surrounding portion. The invention also relates to rod-shaped articles which are obtained in accordance with the improved method and by using the improved apparatus.
German Pat. No. 11 64 907 discloses the making of cigarettes which are provided with axially extending holes as a result of the utilization of a stationary mandrel which is embedded in the tobacco stream and continuously discharges a stabilizer in order to avoid clogging or filling of the hole which is formed by the mandrel.
British Pat No. 1,086,443 discloses a cigarette which has a centrally located hole bounded by a cylindrical surface, or which has a centrally located core of lesser density.
Published British patent application No. 2 150 408 discloses a method of forming a cigarette filler with a less densified inner region. The method includes forming a tobacco stream having a U-shaped cross-sectional outline and closing the stream by bending the legs of the U toward each other.
Published British patent application No. 2 150 008 discloses a method which is also used to form a tobacco filler having a softer central portion. The filler is obtained by forming two tobacco streams each of which has a U-shaped cross-sectional outline and by superimposing one of the streams upon the other. The thus superimposed streams are then densified while surrounding a stationary mandrel.
A drawback of heretofore known proposals is that the cigarettes must be produced in specially designed machines deviating completely from those which are used for the making of conventional cigarettes.